The warning comes as the European Patent Office (EPO) in Munich finds itself the target of fresh criticism over its decision to grant US company Myriad Genetics exclusive rights to the ‘breast cancer gene’.

The company is now attempting to prevent anyone else from using two genes it has isolated to test patients’ likelihood of developing the killer disease.

Myriad has instructed laboratories in the US and Canada to halt their screening programmes, so that it can be the sole supplier of the test.

The firm charges 2,800 euro per patient for its test.

Laboratories across the EU have admitted knowingly infringing the Myriad patents by continuing to monitor the breast cancer genes in patients with a high risk of developing the disease.

“We haven’t stopped using it and we will continue to offer these tests,” said Gert Matthijs, head of the Molecular Genetics Laboratory at Belgium’s Leuven University.

“We have a commitment to our patients,” he added.

“Most genetic labs in Europe feel the same way – we’re very well aware that we’re infringing patent law, but there’s nothing we can do about it.”

The Leuven lab is a member of Belgium’s Society for Human Genetics, which has been joined by similar organisations in the Netherlands, France, Germany and Denmark in contesting three Myriad patents covering the main breast cancer gene known as BRC A1.

The organisations are also likely to oppose Myriad’s application for a fourth patent covering another DNA sequence linked to the disease, called BRC A2.

Matthijs described the US company’s refusal to licence use of the genes as “unheard of in the field”, and said screening centres could face ruinous bills if the EPO rules against their challenges in up to two years’ time.

“If the outcome is bad the company can take us to court and ask us to pay them back for all the testing we’ve done over that time,” said Matthijs. “Then all our centres will be bankrupt.”

Myriad’s opponents have won overwhelming support from MEPs, who last year voted to condemn the EPO patent decisions, appealing to the non-EU body to respect the principle of “non-patentability of life”.

“This is not an invention, it’s a discovery,” said Belgian deputy Bart Staes. “This is something that occurs in nature.”

Staes is pressing the European Commission to say whether the EPO patents comply with the 1998 directive on biotechnological inventions. Although one article stipulates that the human body cannot be patented, another states that ‘isolated’ parts of organisms can.

The EPO maintains its decisions are clearly in line with the directive.

“If a gene sequence has been isolated or reproduced by technical means then it’s already more than a discovery, and it can be patented,” said EPO patent lawyer Rainer Moufang.

“The mere fact that something exists in nature is not a reason to deny a patent.”

However, Frits Bolkestein, the commissioner with responsibility for intellectual property, promised that the review provided for by the directive would be thorough.

“The Commission intends to conduct a detailed study into the issue of the scope of protection for inventions relating to genetic sequences,” Bolkestein said.